Dopamine has been reported as being useful in treating congestive heart failure and shock. In addition, certain amino acid amides of dopamine have been found useful as renal vasodilators and antihypertensive agents, (for example, see U.S. Pat. No. 3,676,492). However, compounds disclosed in the just mentioned patent and others which are used as renal vasodilators have the disadvantage of low potency upon oral administration.
Most of the dopamine, or dopamine generating compound is not utilized to produce the desired activity because it is inactivated too rapidly by metabolic processes in the warm-blooded organisms. While the amount of dopamine necessary to produce the renal vasodilation is rather small, a great quantity of the dopamine or dopamine-generating compound have to be administered to provide for the large metabolic wastage.
It would be a distinct advance in the art if a compound could be protected chemically against the rapid metabolic degradation, since it presumably would decrease the amount of the compound to be administered to produce the pharmacological effect.